allow linking from c++
allow linking from c++

libsocketcan with c++ fails linking.

Signed-off-by: Kurt Van Dijck <bd26f7377381090a3a0fab34a7ac444b3e4756b5@eia.be>
Signed-off-by: Marc Kleine-Budde <4a0ea1158d3cc63151119c05b1bff00c0bdbf421@pengutronix.de>

lalten/libsocketcan,lalten/libsocketcan,lalten/libsocketcan